Printing medium feeding apparatus and image forming apparatus using the same

ABSTRACT

An image forming apparatus includes a body, a photosensitive drum, an openable and closable member openably and closably formed at the body and having a transfer roller which is opposed to the photosensitive drum and transfers an image onto a printing medium, a printing medium pushing member pushing the printing medium to an outside of the body in association with an opening and a closing of the openable and closable member, an elastic member elastically supporting the printing medium pushing member to the outside of the body, and a pressing member formed at one side of the openable and closable member to press the printing medium pushing member toward an inside of the body.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2005-94588, filed on Oct. 7, 2005, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a printing medium feeding apparatus and an image forming apparatus using the same. More particularly, the present invention relates to a printing medium feeding apparatus in which a printing medium jam in a printing medium feeding passage can be easily removed, and an image forming apparatus using the same.

2. Description of the Related Art

Generally, an image forming apparatus has an openable and closable guide member which guides a printing medium onto a paper medium feeding passage. If a printing medium jams in the paper medium feeding passage, the guide member is opened to remove the printing medium. However, if a long printing medium is jammed between a feeding roller upstream of the paper medium feeding passage and a feeding roller downstream of the paper medium feeding passage, or if the printing medium is stuck to the paper medium feeding passage by static electricity, it is difficult to pull the printing medium out of the image forming apparatus body.

There have been various attempts to address these problems. Japanese Patent Publication No. 9-290942, which is hereby incorporated by reference in its entirety, discloses one example of a printing medium feeding apparatus which attempts to address these problems. FIG. 1 shows the structure of the printing medium feeding apparatus of the image forming apparatus disclosed by Japanese Patent Publication No. 9-290942.

Referring to FIG. 1, a guide member 8 forming a part of a paper medium feeding passage of an image forming apparatus is opened toward the outside of the image forming apparatus body to expose the paper medium feeding passage so that a printing medium 2 may be removed. The image forming apparatus further comprises a paper medium push-out member 21 for pushing out a paper medium from the inside to the outside of the paper medium feeding passage. An interlocking mechanism 22 operates the paper medium push-out member 21 as the guide member 8 is opened.

One end of the interlocking mechanism (or linking member) 22 is spaced away from a first point 15 of the guide member 8 by a certain interval. The other end of the linking member 22 has an elongated hole 22 a so that a shaft 21 b spaced a certain interval away from a second point 20 of the printing medium push-out member 21 is inserted into the elongated hole 22 a and slides in the elongated hole 22 a.

The printing medium push-out member 21 is supported by a spring 23. A leading end portion 21 a of the printing medium push-out member 21 forms a part of the guide member 8 as the printing medium is fed.

The image forming apparatus includes printing medium supply rollers 4 and 5, a feeding roller 10, and registration rollers 11, 12.

With this structure, the guide member 8 pivots toward the outside of the image forming apparatus body and the end portion of the elongated hole 22 a of the interlocking mechanism 22 contacts the shaft 21 b so that the printing medium push-out member 21 can be drawn out. Accordingly, the printing medium 2 in front of the printing medium push-out member 21 can be drawn out by the leading end 21 a of the printing medium push-out member 21.

However, the structure of the printing medium push-out member 21 and the interlocking mechanism 22 of the above-described conventional image forming apparatus is very complicated.

Accordingly, there is a need for a printing medium feeding apparatus which allows for removal of paper jams with a less complicated structure.

SUMMARY OF THE INVENTION

An aspect of the present invention is to address at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a printing medium feeding apparatus in which a jammed printing medium can be easily removed.

Another object of the present invention is to provide an image forming apparatus using the printing medium feeding apparatus.

In accordance with an aspect of the present invention, an image forming apparatus comprises a body, a photosensitive drum disposed in the body, and an openable and closable member disposed on the body. The openable and closable member comprises a transfer roller disposed opposite to the photosensitive drum. A printing medium pushing member pushes the printing medium towards an outside of the body in association with an opening of the openable and closable member. An elastic member biases the printing medium pushing member towards the outside of the body, and a pressing member is formed at one side of the openable and closable member for pressing the printing medium pushing member towards the inside of the body.

The printing medium pushing member may comprise a support portion hinged to the body, and a printing medium pushing portion extending from one end of the support portion to push the printing medium.

The elastic member may comprise a wire spring, and a first end of the elastic member may be connected with the printing medium pushing member and a second end of the elastic member may be with the body.

The wire spring may comprise a hook portion and a lock portion.

The support portion of the printing medium pushing member may comprise a wire spring locking portion to accommodate the hook portion of the wire spring, and the support portion may have a groove to accommodate an outer surface of the lock portion of the wire spring.

The pressing member may comprise a pressing protrusion for contacting the support portion of the printing medium pushing member.

A registration unit may be disposed upstream of the photosensitive drum for aligning a leading end of the printing medium, and a fixing unit may be disposed downstream of the photosensitive drum for fixing an image onto the printing medium.

The printing medium pushing member may be disposed between the registration unit and the photosensitive drum on a printing medium feeding passage.

In accordance with another aspect of the present invention, a printing medium feeding apparatus of an image forming apparatus comprises an openable and closable member adapted to be disposed on a body of an image forming apparatus, the openable and closable member forming a portion of a printing medium feeding passage, the openable and closable member exposing the printing medium feeding passage when opened, a printing medium pushing member for pushing a printing medium away from the printing medium feeding passage in cooperation with the openable and closable member, an elastic member biasing the printing medium pushing member away from the printing medium feeding passage, and a pressing member formed at one side of the openable and closable member for pressing the printing medium pushing member towards the printing medium feeding passage.

The printing medium pushing member may comprise a support portion hinged to the body, and a printing medium pushing portion extending from one end of the support portion to push the printing medium.

The elastic member may comprise a wire spring, and a first end of the elastic member may be connected with the printing medium pushing member and a second end of the elastic member may be connected with the body.

The wire spring may comprise a hook portion and a lock portion.

The support portion of the printing medium pushing member may comprise a wire spring locking portion to accommodate the hook portion of the wire spring, and the support portion may have a groove to accommodate an outer surface of the lock portion of the wire spring.

The openable and closable member may further comprise a first feeding roller for feeding the printing medium and a second feeding roller which is opposed to the first feeding roller.

The pressing member may comprise a pressing protrusion for contacting the support portion of the printing medium pushing member.

In accordance with another aspect of the present invention, an image forming apparatus comprises a body and a photosensitive drum for forming images disposed on the body. A transfer roller is disposed opposite to the photosensitive drum to form a transfer nip. A means for registering a printing medium is disposed upstream of the photosensitive drum, and a means for fixing an image on a printing medium disposed downstream of the photosensitive drum. The photosensitive drum, transfer roller, registration means, and fixing means define a printing medium feeding path. A pushing member pushes the printing medium away from the printing medium feeding path, and is biased away from the printing medium feeding path. An openable and closable member is disposed on the body for exposing a portion of the printing medium feeding path. The openable and closable member comprising a pressing member for pressing the printing medium pushing member towards the printing medium feeding path.

The printing medium pushing member may comprise a support portion pivotably disposed on the body, and a printing medium pushing portion extending from the support portion to push the printing medium.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view of a printing medium feeding apparatus of a conventional image forming apparatus;

FIG. 2 is a view of part of a structure of an image forming apparatus according to an exemplary embodiment of the present invention;

FIG. 3 is a view of the image forming apparatus of FIG. 2 when an openable and closable member is opened;

FIG. 4 is an enlarged view of a printing medium pushing member according to an exemplary embodiment of the present invention; and

FIG. 5 is an exploded perspective view of the printing medium pushing member shown in FIG. 4.

Throughout the drawings, the same reference numerals will be understood to refer to the same elements, features, and structures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The matters defined in the description such as a detailed construction and elements are provided to assist in a comprehensive understanding of the embodiments of the invention. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. Also, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

FIG. 2 is a view of part of a structure of an image forming apparatus according to an exemplary embodiment of the present invention, and FIG. 3 is a view of the image forming apparatus of FIG. 2 when an openable and closable member is opened.

Referring to FIGS. 2 and 3, a photosensitive drum 103 is provided in an image forming apparatus body 101. A transfer roller 105 is disposed opposite the photosensitive drum 103 so that an image is transferred onto a printing medium P which passes between the transfer nip formed between the photosensitive drum 103 and the transfer roller 105.

The transfer roller 105 is disposed on an openable and closable member 107 which opens a part of the image forming apparatus body 101. One end of the openable and closable member 107is hinged so that it pivots about a hinge axis 109. The openable and closable member 107 may be pivoted by a certain angle so as to open and close the image forming apparatus body 101. The transfer roller 105 with contacts or is separated from the photosensitive drum 103 depending on whether the openable and closable member 107 is opened or closed.

A registration unit 110 is further included upstream of the photosensitive drum 103. Upstream refers to a direction opposite the printing medium P feeding direction, that is, the direction opposite to the direction of the arrow A in FIG. 2. The registration unit 110 registers a printing medium by temporarily stopping the printing medium P before the printing medium P is fed to the transfer roller 105 to align a leading end of the printing medium P. The registration unit 110 comprises a drive registration roller 111 and an idle registration roller 113.

A fixing unit 130 is included downstream of the photosensitive drum 103. The fixing unit 130 heats and presses the image transferred onto the printing medium P by the transfer roller 105 and comprises a heat roller 131 and a press roller 133.

A printing medium pushing member 150 is formed between the registration unit 110 and the photosensitive drum 103 on the printing medium P feeding passage. The printing medium pushing member 150 is rotated to the outside of the image forming apparatus body 101 as the openable and closable member 107 is opened so as to push the printing medium P to the outside of the image forming apparatus body 101 and provide a space in which a user can easily pull out the printing medium P. The openable and closable member 107 has a pressing member 160 that interferes with the printing medium pushing member 150. The pressing member 160 comprises a pressing protrusion 161.

FIG. 4 is an enlarged view of the printing medium pushing member 150 according to an exemplary embodiment of the present invention, and FIG. 5 is an exploded perspective view of the printing medium pushing member 150.

Referring to FIGS. 4 and 5, the printing medium pushing member 150 comprises a supporting portion 153 rotatably connected with one side of the image forming apparatus body 101 about a hinge axis 151, and a printing medium pushing portion 155 bent at one end of the supporting portion 153 to push the printing medium P.

An elastic member 170 biases the printing medium pushing member 150 towards the outside of the image forming apparatus body 101. At this time, if the openable and closable member 107 is closed, the pressing protrusion 161, which forms the pressing member 160 in the openable and closable member 107, contacts the supporting member 153 so that the elastic member 170 is pressed (refer to FIG. 2).

In contrast, if the openable and closable member 107 is opened, the pressing protrusion 161 is separated from the supporting portion 153 so that the printing medium pushing member 150 is rotated towards the outside of the image forming apparatus body 101 by a restitution force of the elastic member 170 and the printing medium P is pushed towards the outside of the image forming apparatus body 101 (refer to FIG. 3).

the elastic member 170 may be formed in various configurations; however, in the present exemplary embodiment, the elastic member comprises a wire spring 171. One end of the wire spring 171 comprises a hook portion 171 a and a lock portion 171 b disposed on the support portion 153 of the printing medium pushing member 150. The wire spring may be formed, for example, by a number of bending operations.

To fix the wire spring 171, a wire spring locking portion 157 is formed at one side of the support portion 153 of the printing medium pushing member 150 to lock the hook portion 171 a of the wire spring 171, and a groove 159 is formed at the support portion 153 to receive an outer surface of the lock portion 171 b of the wire spring 171.

A first end of the wire spring 171 is connected with the printing medium pushing member 150 and a second end of the wire spring 171 is connected with one side of the image forming apparatus body 101.

The operation of removing a jammed printing medium from the image forming apparatus according to an exemplary embodiment of the present invention will now be described.

Referring to FIG. 2, as an image forming operation is performed, the leading end of the printing medium P fed by a printing medium feeding unit (not shown) is aligned by the registration unit 110. Then, the printing medium P is fed to the transfer nip between the photosensitive drum 103 and the transfer roller 107 so that an image is transferred to the printing medium P. The fixing unit 130 heats and presses the transferred image to fix the image on the printing medium P.

While the image forming operation is performed, the openable and closable member 107 is closed and the pressing protrusion 161, which is the pressing member 160 in the openable and closable member 107, presses the support portion 153 of the press medium pushing member 150. Accordingly, the printing medium pushing member 150 does not interfere with the printing medium feeding passage.

Referring to FIG. 3, if the printing medium P is jams during the image forming operation, the openable and closable member 107 is opened. The pressing protrusion 161 of the openable and closable member 107 is separated from the support portion 153 of the printing medium pushing member 150. Accordingly, the printing medium pushing member 150 is rotated towards the outside of the image forming apparatus body 101 by a restitution force of the wire spring 171, which is the elastic member 170, so that the printing medium P is pushed towards the outside of the image forming apparatus body 101. Accordingly, the printing medium P forms a curl C so that a space is formed to easily remove the jammed printing medium. With the space, the printing medium P can be easily pulled out from the image forming apparatus body 101.

In the present exemplary embodiment, the printing medium pushing member 150 is disposed between the photosensitive drum 103 and the registration unit 110, and the transfer roller 107 is disposed opposite the photosensitive drum 103.

However, this is only an example of a suitable configuration. The printing medium pushing member 150 may be formed at any position on the printing medium feeding passage. In other words, the printing medium pushing member 150 may be applied to any type of image forming apparatus in which the printing medium feeding passage is opened to remove a printing medium P.

As described above, if a printing medium P is jammed and the openable and closable member is opened, the printing medium is pushed towards the outside of the image forming apparatus body so that a user can easily pull out the printing medium.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 

1. An image forming apparatus comprising: a body; a photosensitive drum disposed in the body; an openable and closable member disposed on the body, the openable and closable member comprising a transfer roller disposed opposite to the photosensitive drum; a printing medium pushing member for pushing the printing medium towards an outside of the body in association with an opening of the openable and closable member; an elastic member biasing the printing medium pushing member towards the outside of the body; and a pressing member disposed at one side of the openable and closable member for pressing the printing medium pushing member towards the inside of the body.
 2. The apparatus as claimed in claim 1, wherein the printing medium pushing member comprises: a support portion hinged to the body; and a printing medium pushing portion extending from one end of the support portion to push the printing medium.
 3. The apparatus as claimed in claim 2, wherein the elastic member comprises a wire spring.
 4. The apparatus as claimed in claim 3, wherein a first end of the elastic member is connected with the printing medium pushing member and a second end of the elastic member is connected with the body.
 5. The apparatus as claimed in claim 4, wherein the wire spring comprises a hook portion and a lock portion.
 6. The apparatus as claimed in claim 5, wherein the support portion of the printing medium pushing member comprises a wire spring locking portion to accommodate the hook portion of the wire spring, and the support portion comprises a groove to accommodate an outer surface of the lock portion of the wire spring.
 7. The apparatus as claimed in claim 2, wherein the pressing member comprises a pressing protrusion for contacting the support portion of the printing medium pushing member.
 8. The apparatus as claimed in claim 1, further comprising: a registration unit disposed upstream of the photosensitive drum for aligning a leading end of the printing medium; and a fixing unit disposed downstream of the photosensitive drum for fixing an image onto the printing medium.
 9. The apparatus as claimed in claim 8, wherein the printing medium pushing member is disposed between the registration unit and the photosensitive drum on a printing medium feeding passage.
 10. A printing medium feeding apparatus of an image forming apparatus comprising: an openable and closable member adapted to be disposed on a body of an image forming apparatus, the openable and closable member forming a portion of a printing. medium feeding passage, the openable and closable member exposing the printing medium feeding passage when opened; a printing medium pushing member for pushing a printing medium away from the printing medium feeding passage in cooperation with the openable and closable member; an elastic member biasing the printing medium pushing member away from the printing medium feeding passage; and a pressing member disposed at one side of the openable and closable member for pressing the printing medium pushing member towards the printing medium feeding passage.
 11. The apparatus as claimed in claim 10, wherein the printing medium pushing member comprises: a support portion hinged to the body; and a printing medium pushing portion extending from one end of the support portion to push the printing medium.
 12. The apparatus as claimed in claim 11, wherein the elastic member comprises a wire spring.
 13. The apparatus as claimed in claim 12, wherein a first end of the elastic member is connected with the printing medium pushing member and a second end of the elastic member is connected with the body.
 14. The apparatus as claimed in claim 13, wherein the wire spring comprises a hook portion and a lock portion.
 15. The apparatus as claimed in claim 14, wherein the support portion of the printing medium pushing member comprises a wire spring locking portion to accommodate the hook portion of the wire spring, and the support portion comprises a groove to accommodate an outer surface of the lock portion of the wire spring.
 16. The apparatus as claimed in claim 10, wherein the openable and closable member further comprises a first feeding roller for feeding the printing medium and a second feeding roller which is opposed to the first feeding roller.
 17. The apparatus as claimed in claim 10, wherein the pressing member comprises a pressing protrusion for contacting the support portion of the printing medium pushing member.
 18. An image forming apparatus comprising: a body; a photosensitive drum for forming images disposed on the body; a transfer roller disposed opposite to the photosensitive drum to form a transfer nip; means for registering a printing medium disposed upstream of the photosensitive drum; means for fixing an image on a printing medium disposed downstream of the photosensitive drum, the photosensitive drum, transfer roller, registration means, and fixing means defining a printing medium feeding path; a pushing member for pushing the printing medium away from the printing medium feeding path, the pushing member being biased away from the printing medium feeding path; and an openable and closable member disposed on the body for exposing a portion of the printing medium feeding path, the openable and closable member comprising a pressing member for pressing the printing medium pushing member towards the printing medium feeding path.
 19. The apparatus as claimed in claim 18, wherein the printing medium pushing member comprises: a support portion pivotably disposed on the body; and a printing medium pushing portion extending from the support portion to push the printing medium. 